This invention relates to flexible bulk containers used for the handling and storage of flowable materials. More particularly, the invention is directed toward a container having means affixed therein for maintaining the shape and structural integrity of the container while it is partially or completely filled with flowable materials.
Flexible bulk containers carrying flowable materials are generally transported by the truck load wherein stacks of the flexible containers are placed into the truck. As with any material transport, it is important from an efficiency standpoint to stack and load the flexible containers in an ordered manner. Generally, flexible containers are designed to take on a cubicle shape when completely full. However, because of the flexible material from which the walls of the container are made, the containers tend to bulge when filled with the flowable materials. Accordingly, the containers take on a shape representative of a cube but having rounded edges and protruding sides. Because of the container's tendency to take on this shape, the containers become unaccommodating to efficient loading. Accordingly, valuable transportation space can be lost.
It is, therefore, desirable to maintain the containers in a predictable and primarily cubicle shape. As such, the cubicle containers save space and allow more material and containers to be transported in a single load. The structural integrity of the flexible containers can be maintained in numerous ways, many of which are inconvenient to the handling of the containers. Supports located on the outer skin of the containers and containers made out of a material which is less flexible can be used. However, these methods are not compatible with the advantages of a purely flexible container such as the flexible container's light weight and easy storage when they are not being used. In the prior art, flexible containers using inner structural support means are disclosed.
U.S. Pat. No. 5,076,710 to Derby for example discloses a flexible container having inner support members (FIG. 11) in which the members assist in maintaining the cubicle structure of the container. Similarly, the Derby patent also discloses a prior art container in FIG. 10 having inner bridge members for maintaining the structure of a more cylindrically-shaped container. The Derby patent uses bridge panels which span each corner of the container on the interior surface. The panels assist in maintaining the cubicle structure of the container. However, because the panels are located so close to each corner of the container, the container tends to have smaller areas where the flowable materials may have a tendency to become lodged. Also, because the panels are not attached in any manner to each other, the Derby invention requires substantially more work in attaching the panels to the interior surface of the flexible container.